The use of computers and many other electronic devices has become generally dependent on the use pointing devices for communicating, usually in connection with a graphical computer interfaces. Pointing devices are used in general office computing such as word processing, spreadsheet analysis, and data base management. Similarly, pointing devices are used in graphical document preparation and design such as may be done by design engineers, product designers, and architects who use computer-aided design and drafting applications. Additionally, pointing devices of various types are used as remote controls in such areas as vehicle controls, industrial and consumer machine and appliance controls, mapping systems, entertainment systems, and many other to facilitate visual interaction between a user and a computer or computer-based system.
A common pointer device is the so-called “mouse.” The traditional mouse comprises basically a movable element that can be positioned by hand at arbitrary locations usually on a planar target surface. The mouse can electronically communicate mouse movements in Cartesian coordinates to a computer. The mouse typically also includes one or more control buttons, selectors, or other actuators that can be used to send commands to applications running on the computer. For example, the mouse might include a button with which the user can command a computer application to “select” an item pointed to on the computer display.
The mouse gets its name from a perceived mouse-like similarity of the body of the device with a communication cable extending from one end. However, various forms of wireless “mice” are available, and yet the terminology persists.
There exist other forms of computer pointing and commanding devices such as trackballs, joysticks, light pens, touch pens, and the like which provide the same or very similar functionality as a traditional mouse. Likewise, pointing and commanding devices such as touch pads, touch screens, and the like offer mouse-like capabilities. However, the more traditional mouse-type devices remain in use.
In 1970, Douglas Engelbart was awarded a patent for an X-Y Position Indicator for a Display System (U.S. Pat. No. 3,541,541), which, along with the development of the graphical interface, provided for operating a computer without typing commands. The Engelbart system, which includes a mouse, was configured to communicate to a computer the instantaneous position of the mouse moving on a planar work surface with planar hand movements. The Engelbart mouse was capable of digitally encoding signals from friction-driven orthogonal mouse wheels as the mouse was moved about on the work surface. There have been many subsequent improvements in encoding technologies for detecting motion of a mouse on a work surface and transmitting a signal to accordingly position a cursor on a computer display. The Engelbart configuration of friction-driven, orthogonally angled tracking wheels was followed by improvements such as a friction driven spheres or balls, the rotation of which were encoded via friction driven discs or optical detectors. The friction driven ball then gave way to technologies for directly sensing the motion of the mouse relative to the supporting work surface by optical means. These technologies eliminated problems with friction failure that sometimes occurred while the mouse was in motion. Such developments improved the sensitivity and reliability of motion sensing in the context of computer input devices.
As prior art mouse devices developed, scroll wheel actuators were introduced. The scroll wheel was generally acknowledged as a potential Z-axis positioner for 3-D graphical work. It is used more generally, however, as a special selector or actuator for performing menu scrolling.
Some mouse-type devices based on non-planar hand movement have been developed. For example, Barnes (U.S. Pat. No. 5,774,113) disclosed a three-directional mouse on a pedestal. The Barnes device comprises a spherical ball resting on an elevated support and associated electronics that detect the angular orientation of the ball relative to the support. A button was provided on the Barnes device for signaling the computer to move an on-screen icon in the direction indicated by the current ball orientation. Adams (U.S. Pat. No. 5,990,871) disclosed a similar device having a relatively large ball supported on a generally conical or mountain-like fixed base. The Adams ball provides as an ambidextrous hand support. A command button for actuation by a finger of the hand was included in the Adams device. Suzuki (U.S. Pat. No. 6,130,664) disclosed an input device designed to operate on a non-planar surface. A curved lower surface of the input device of Suzuki is configured to rest on any work surface and to roll along the surface. Velocity sensors are used in the Suzuki device to detect motion of the device relative to the surface.
In some cases, computer operators working in graphic design, engineering design, architectural design, and the like use so-called trackball devices as pointers for cursor control. Such devices are said to provide for selection of a point, such as a specific display pixel, without the selection action moving the device and thus the display cursor. Pressing a selector button without at least some movement may be found in some cases to be difficult with some mouse devices because the action of pressing the selector key often moves the mouse body and thus the cursor. However, cursor motions driven by a track ball device are said to be counterintuitive to many users relative to a combination of X-axis motion and Y-axis motion.
As mentioned above, the typical mouse-type device generally includes one or more control actuators, selectors, or buttons for sending application specific commands to the computer along with the position or movement data for the mouse. A typically used selector key may be pressed by the user's finger and caused to contact an electrical switch configured within the device. A typically-utilized electrical switch of high reliability and low cost has a very short actuation displacement of about one sixty-fourth of an inch (0.015 inch, 0.4 mm). Such devices are typically configured in a mouse where the switch is directly actuated by pressing a key cover positioned directly over the switch. Some users find this configuration unsuitable as to the working tactile sensation of actuation.
Currently available mouse-type devices are said to contribute to work-related health problems. For example, mouse usage is thought to be a factor in repetitive stress injuries among information technology workers. Complaints of office workers and other information technology users may include symptoms of repetitive motion disorders possibly related to extended periods of computer mouse usage. Using the human hand to move a mouse on a planar surface is thought to be inherently incompatible with the functional anatomy of the human hand and arm. Such movements may require sizable extensions and retractions of the arm and hand. Wired mouse devices also may sometimes present impediments to movement relative to the wire or cable connecting the mouse to the computer. In some situations, excessive tension may be produced in hand and arm muscles, especially when making precise mouse movements and command selections. Overuse and fatigue of hand and arm muscles may result. Moreover, the placement and configuration of control buttons, thumbwheels, trackballs and the like may be associated with unusual flexion and extension of the fingers which are thought to be tiring and uncomfortable.
There remains a need for a mouse-type device that is ergonomically friendly to the human hand and arm and capable of effective precise pointing and command generation.